| 摘要 |
To provide a digital signal combining circuit having a function to combine two digital signals converted from two analog signals and a function to compensate for nonlinearity of two A/D converters upon input of one analog input signal and to convert the analog input signal to a digital signal with S/N ratio improved by about 3 dB. The digital signal combining circuit has a first inversion circuit ( 3 ), a second inversion circuit ( 4 ), an A/D converter (ADC 1 ), a third inversion circuit ( 6 ), a fourth inversion circuit ( 7 ), another A/D converter (ADC 2 ), a digital inversion circuit ( 11 ) and a digital mixer circuit ( 10 ). When only one analog input signal is converted to a digital output signal, the analog input signal is inputted into a positive input of the A/D converter (ADC 1 ), an inverted analog input signal is inputted into a negative input of the A/D converter (ADC 1 ), the inverted analog input signal is inputted into a positive input of the other A/D converter (ADC 2 ), the analog input signal is inputted into a negative input of the other A/D converter (ADC 2 ), and the digital inversion circuit ( 11 ) inverts a digital output from the other A/D converter (ADC 2 ).
|
